When an object of a photographing operation is moving at a high speed, a photographer has conventionally performed photographing using a high-speed shutter to obtain an image of the object without blurring, or performed photographing while panning the camera following the motion of the object. When the high-speed shutter is used, as the time to expose image sensing devices is reduced, the blurring of the object is reduced. However, in this case, all of the object is image-sensed without blurring, and therefore the obtained image lacks a realistic sensation that the object is moving. On the other hand, when photographing is performed with a camera panning to keep up with the motion of the object so as to obtain a realistic moving sensation, an image where the blurring of the object is reduced but the background is blurred (an image with follow shot effects) is obtained. However, the blurring of the object cannot be completely prevented due to the difference between the speed of motion of the object and the speed of the camera panning and camera shaking in a direction different from the direction of the motion of the object.
Further, upon night photographing to obtain an image where a car tail lamp or the like is flowing, the camera is fixed with a tripod stand or the like and exposure is performed over an extended time period, and an image where only a moving object appears to be flowing (an image with lasting effects) can be obtained. However, when the camera cannot be fixed since the tripod stand cannot be used, the entire image is blurred due to camera shaking.
As a method for correcting such blurring, an optical anti-shake system to perform image blur correction by detecting an acceleration, an angular acceleration, an angular velocity, an angular displacement and the like with a laser gyroscope and the like, appropriately performing calculation processing based on the results of detection, and driving a correcting optical device to decenter an photographing optical axis is known. Further, a method for performing image sensing plural times for exposure periods not to cause camera shaking and composition images obtained by the plural times of image sensing while correcting image shifts to obtain an image by long-hour exposure image sensing (composite image) is known (for example, Japanese Patent Application Laid-Open No. 5-7336).
Recently, downsizing of digital cameras is promoted in comparison with silver-chloride compact cameras. Especially, a camera having an SXGA-class image sensing device is so downsized that it can be included in a mobile electronic device (for example, a cellular phone).
When the above-described optical anti-shake system is incorporated in such a camera, further downsizing of the blur correcting optical device is required or downsizing of the shake detection unit, such as a laser gyroscope, is required.
However, downsizing of the blur correcting optical device is limited since it supports a correction lens and drives the lens with high accuracy. Further, as most of currently used shake detection units utilize an inertia force, when such shake detection unit is downsized, its detection sensitivity is lowered, and blur correction with high accuracy cannot be performed.
Further, as blurring applied to a camera, angular blurring about a predetermined axis and shift blurring by parallel shaking of the camera are detected. The angular blurring can be corrected by the optical anti-shake system. However, the shift blurring cannot be corrected without difficulty. Especially, as a camera is downsized, the shift blurring is increased.
On the other hand, in the anti-shake method as disclosed in the above Japanese Patent Application Laid-Open No. 5-7336, as a high-speed shutter not to cause blur in one image is employed, an image with follow shot effects or lasting effects as described above cannot be obtained by repeating image sensing and performing a composition of obtained images.